The present invention relates to a navigation device which performs three dimensional display.
FIG. 18 is a block diagram showing a conventional navigation device. 101 is a map data base which is provided with polygon data for the three dimensional display of roads, buildings and the like. Furthermore 102 is an overall operation control section which controls the operation of the overall device. 103 is an image generation processing section which generates images and the like for three dimensional display. 104 is an image display device.
Next the operation of the invention will be explained.
The image generation processing section 103 calculates a map display range based on display perspective selection data and automobile position data supplied from the overall operational control section 102. The image generation processing section 103 reads road data and building polygon data which form the basis of the image, converts to a point coordinate system and perspective projection and generates an image for display. A three dimensional map of a fixed geographical point is displayed on the image display device 104 by the selection of a display perspective.
Since the conventional navigation device is constructed in such a way, it has been a problem that intersections are merely displayed in three dimensional format without any information with respect to such things as lanes on the road or the like.
In order to solve the above problem, it is a purpose of the present invention to provide a navigation device which can display vehicle lane information in a clear way when performing three dimensional display when approaching an intersection.
The navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided with a map data base which stores the number of road vehicle lanes on a road which enters an intersection, a road width display data base which stores road width display data so that each road vehicle lane width decreases depending on the number of road vehicle lanes and the overall road width increases, a road width display data extraction means which, when approaching an intersection, extracts a number of vehicle lanes which enter the corresponding intersection from the map data base and which extracts road width display data corresponding to the number of vehicle lanes from the road width display data base and a display means which displays based on the extracted road width display data.
By this arrangement, the number of vehicle lanes can be easily understood and the display is easy to view.
The vehicle navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided with a map data base which stores categories of data which discriminate lanes into those which continue straight ahead(hereafter straight lanes), left-hand lanes, right-hand lanes and branching lanes, a sign designation means which extracts a corresponding category of data from the map data base when approaching an intersection and which designates a sign corresponding to the category of data with respect to the vehicle lane based on the extracted category of data.
By this arrangement, it is easy to view lane information on the subject intersection.
The vehicle navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided at least with a map data base which stores vehicle lane information of roads entering each intersection, a vehicle lane information extraction means which extracts vehicle lane information of roads which enter the corresponding intersection from the map data base and a display means which displays only vehicle lane information of entering roads, extracted by the vehicle lane information extraction means, as vehicle lane information.
Due to the arrangement above, the necessary vehicle lane information is extremely easy to view.
The vehicle navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided with a map data base which stores destination names of roads which exit each intersection and lane information on roads which enter each intersection, a lane information storage determination means which determines whether or not lane information is stored in the map data base, an extraction means which extracts corresponding lane information from the map data base when it has been determined that such lane information is stored and which extracts a corresponding destination name from the map data base when it is determined that no lane information is stored, and a display means which displays said lane information when lane information is extracted and which displays said destination name when it is determined that a destination name has been extracted.
By such an arrangement, it is extremely easy to view lane information.
The vehicle navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided with a map data base which stores the name of each intersection, an intersection name extraction means which extracts an intersection name for the subject intersection and the names of sub-intersections in the vicinity of the subject intersection from the map data base when approaching a subject intersection which should be indicated, and a display means which respectively discriminates and displays an intersection name for the subject intersection and the names of sub-intersections extracted by the intersection name extraction means.
In this way, it is easy to discriminate the names of intersections and sub-intersections at the subject intersection.
The vehicle navigation device of the present invention relates to a navigation device which performs three dimensional display when approaching an intersection. The navigation device is provided with a map data base which stores vehicle lane information on roads which enter each intersection, a vehicle lane information extraction means which extracts vehicle lane information of the subject intersection when a subject intersection is approached which should be indicated, and a display means which displays the vehicle lane information of the extracted subject intersection point after a sub-intersection point before the subject intersection.
By the arrangement above, it is possible to change lanes with appropriate timing.